Kelco MF20-B Super Sensitive Micro Flow Switch for Chemical Dosing Pumps Low/Pulsed Flow

The Kelco MF20-B Micro Flow Switch is an ultra-sensitive inline flow sensor designed for detecting extremely low flows in clean liquid applications. As a refined version of Kelco’s P20 switch, it can detect flows as low as 350mL per hour and up to 25L/min, making it ideal for monitoring chemical dosing and metering pumps, batch processes, and low-flow industrial systems.

Constructed from glass-reinforced polypropylene with Viton® seals and PVC spigots, the MF20-B contains no metal wetted parts, ensuring excellent corrosion resistance in aggressive liquids such as acids, alkalis, and chemical solutions. Supplied with three interchangeable pistons (A, B, C) for adjustable sensitivity, it can handle both continuous and pulsed flows with a stable electrical output.

The MF20-B is equipped with a dry contact SPST reed switch (40W, 1A max), making it suitable for PLC signalling, telemetry, and general control circuits. The switch is supplied with tube flare fittings (6mm, 8mm, 12mm) and 15NB PVC spigots with unions for flexible installation in dosing systems.

FEATURES

• Australian-made ultra-sensitive micro flow switch
• Detects flows <350mL/hr up to 25L/min
• Glass-reinforced polypropylene body with Viton® seals – corrosion resistant
• No metal wetted parts – ideal for aggressive liquids
• Three interchangeable pistons for adjustable sensitivity
• Suitable for continuous or pulsed flows
• Low head loss, vertical mounting (flow upward)
• SPST reed switch (40W, 1A max) – PLC and general control use
• IP67 weatherproof housing with 20mm cable gland
• Supplied with tube flare fittings & 15NB PVC spigots/unions
  

APPLICATIONS

• Chemical dosing pump monitoring
• Batch control and process verification
• Low-flow chemical injection monitoring
• Loss-of-prime protection for dosing systems
• Laboratory and research liquid flow detection
• Water treatment and cooling tower systems

SPECIFICATIONS

• Flow range: 0.32–12.8 L/hr depending on piston
• Max pressure: 18 bar (260 psi)
• Burst pressure: 9700 kPa (1400 psi)
• Liquid temp: -30°C to 60°C (max 1 bar at 60°C)
• pH range: 1–14
• Electrical rating: SPST NO reed switch, 40W, 240V AC / 200V DC, 1A max resistive load
• Mounting: Vertical, flow upward only
• Weatherproof rating: IP67